A5046501522- Rare-earth and actinide compounds
- Muon and positron interactions and applications
- Energy Efficient Wireless Sensor Networks
- Advanced Chemical Physics Studies
- Spacecraft Dynamics and Control
- Mobile Ad Hoc Networks
- Space Satellite Systems and Control
- Heusler alloys: electronic and magnetic properties
- Astro and Planetary Science
- Physics of Superconductivity and Magnetism
- Spacecraft Design and Technology
- Advanced Condensed Matter Physics
- High-pressure geophysics and materials
- Iron-based superconductors research
- Intermetallics and Advanced Alloy Properties
- Organic and Molecular Conductors Research
- Magnetism in coordination complexes
- Magnetic and transport properties of perovskites and related materials
- Robotic Path Planning Algorithms
- Nuclear physics research studies
- X-ray Spectroscopy and Fluorescence Analysis
- Wireless Networks and Protocols
- Nuclear Physics and Applications
- Distributed Control Multi-Agent Systems
- Dynamics and Control of Mechanical Systems
Japan Aerospace Exploration Agency
2022
Institute of Space and Astronautical Science
2022
Nihon University
1993-2021
The University of Tokyo
1980-2021
Oki Electric Industry (Japan)
2005-2017
Tokyo Denki University
2015
Fukushima University
2013
University of Fukui
2005-2006
Gakushuin University
2002-2005
Kagoshima University
1981-1983
We report the discovery of a pressure-induced heavy fermion superconductivity in nonmagnetic orbital ordering state cubic compound PrTi(2)Al(20). In particular, we found that transition temperature and effective mass associated with are dramatically enhanced as system approaches putative quantum critical point order. Our experiment indicates strong fluctuations may provide glue for Cooper pairing.
Although ground robotic autonomy has gained widespread usage in structured and controlled environments, unknown off-road terrain remains a difficult problem.Extreme, off-road, unstructured environments such as undeveloped wilderness, caves, rubble pose unique challenging problems for autonomous navigation.To tackle these we propose an approach assessing traversability planning safe, feasible, fast trajectory real-time.Our approach, which name STEP (Stochastic Traversability Evaluation...
The electronic structures of the Heusler alloys Co2MnSn, Co2TiSn and Co2TiAl are calculated using SAPW method. common properties characteristics these three seen in their band structures. Whether or not orbital angular momentum is quenched discussed on basis For Co atom alloys, expected to contribute magnetic moment internal field.
This paper presents a design for drop tower test to evaluate numerical model structurally reconfigurable spacecraft with actuatable joints, referred as transformable spacecraft. A mock-up robot 3U-sized is designed fit in limited time and space of the microgravity environment available tower. The performs agile reorientation, nonholonomic attitude control, by actuating joints particular manner. To adapt very short duration test, successive joint actuation maneuver optimized maximize amount...
Magnetic Compton profiles (MCP's) are calculated for iron and nickel by the full-potential linearized augmented-plane-wave (FLAPW) method on basis of local-spin-density approximation. These results in good agreement with experimental data Sakai et al. excellent statistical accuracy. The FLAPW calculations leave slight but noticeable discrepancies MCP's along 〈100〉 〈110〉 directions direction nickel. In case iron, parametrized performed lowering center gravity p states to reasonably describe...
Many computer systems have turned increasingly to control systems, requiring more sophisticated machinery over an ever-widening range. The reliability of the system should be carefully considered in all its aspects. concept a segment is introduced against local malfunctions or failures order save from going down. This paper also describes fault tolerant with dual operation aimed at getting fail-safe feature output and complex features for maintenance improvement system. Three "off-the-shelf"...
High resolution Compton profiles have been measured in the single crystal of CeRu(2)Si(2) above and below Kondo temperature to elucidate change Ce-4f electron from localized itinerant states. Two-dimensional occupation number densities projected on first Brillouin zone, which are obtained after a series analyses, clearly specify difference between The contribution electrons electronic structure is discussed by contrast with band calculation.
The tight-binding orthogonalised plane-wave (TB OPW) method is used to reproduce the band structures obtained by SAPW method. spin-orbit interaction treated perturbation theory calculate orbital angular momentum of Heusler alloys Co2YZ on basis structures. contributions magnetic moment Co in Cp2YZ are 0.1, 0.07 and 0.025 mu B for Co2MnSn, Co2TiSn Co2TiAl respectively.
Taking into account requirements of sensor networks, we need fully-distributed and self-organising control mechanisms which are scalable to the size a network, robust failures nodes, adaptive different dynamically changing topology changes in wireless communication environment. To accomplish this goal, our research group focuses on behaviour biological systems, inherently scalable, robust. In paper, first verify practicality adopting reaction-diffusion equation, explains emergence patterns...
The energy-band structures for ${\mathrm{LaB}}_{6}$ and ${\mathrm{CeB}}_{6}$ are calculated by the full-potential linearized augmented-plane-wave (FLAPW) method on basis of local-density approximation. results FLAPW band calculations applied three-dimensional Lock-Crisp-West (LCW) folded momentum densities (3D LCW FMD's) positron annihilation in within an independent-particle model (IPM). compared with experimental ones reconstructed from two-dimensional angular correlation...
A new method for filtering three-dimensional reconstructed densities is proposed. The algorithm tested with simulated spectra and employed to study the electronic structure of rare-earth compound $\mathrm{La}{\mathrm{B}}_{6}$. For this system, momentum are from theoretical experimental two-dimensional angular correlation electron-positron annihilation radiation (2D ACAR) spectra. results in good agreement band calculated full-potential linearized augmented-plane-wave (FLAPW) within...
In a Kondo lattice, the Luttinger theorem requires $f$ electron degree of freedom to enter Fermi volume in strong-coupling regime, while remains nearly localized. A common hypothesis assumes that shrinks with increasing temperature when decouples from surface breakdown lattice effect. However, experimental evidence for this phenomen is still very scarce. Here, authors demonstrate reconstruction between 14 and 300 K...
An interpolation scheme which is applicable to Heusler alloys developed as an extension of Mueller's method (1966). The topology the Fermi surface determined by this for Cu2MnAl, Pd2MnSn and Ni2MnSn. shapes surfaces these three are very similar majority-spin electrons but different minority-spin electrons. OPW component d estimated on surfaces. respective characteristics seen in proportion components
We have studied the pressure dependence of superconducting transition temperature ${T}_{c}$ filled skutterudite YFe${}_{4}$P${}_{12}$ under various quasihydrostatic pressures up to 8 GPa. DC magnetization measurements 1.2 GPa in a piston-cylinder cell yields linear increase with positive coefficient $d{T}_{c}$/$dP$ $=$ 1 K/GPa. Resistivity cubic anvil apparatus show that increases 9.3 K at GPa, but slope decreases gradually increasing pressure. Besides previously reported...
This paper reports on the manufacturing and evaluation of a solar power sail membrane prototype for OKEANOS project. The in-house was built by Institute Space Astronautical Science, Japan Aerospace Exploration Agency. Mechanical electrical tests were conducted. membrane, thin-film cells, reflectivity control devices good condition after handling. improvements in process design found. fundamentally established. After prototype, improvement plans tried. We have prospect flight model continue...
X-ray form factors have been calculated for metallic vanadium by the APW method. The charge asphericity is estimated using ratios of integrated intensities scattering reflection pairs having same value sin( theta / lambda ). obtained from a state-dependent potential, which was made to reproduce dimensions and shape Fermi hole pocket at N-points, larger than that state-independent potentials. potential are in reasonable agreement with experimental ones determined Weiss Demarco (1965) Diana...
Taking into account requirements of sensor networks, we need fully-distributed and self-organizing control mechanisms which are scalable to the size a network, robust failures nodes, adaptive different dynamically changing topology changes in wireless communication environment. To accomplish this goal, our research group focuses on behavior biological systems, inherently scalable, adaptive, robust. In paper, first verify practicality adopting reaction diffusion equation, explains emergence...
Subpicosecond time-resolved anisotropic transmission spectroscopy has been applied to one of the parent compounds colossal magnetoresistance manganites, orbital-ordered ${\text{LaMnO}}_{3}$, with and without $A$-type antiferromagnetic order. ${\text{LaMnO}}_{3}$ is simplest Mott insulators which facilitates unambiguous interpretation data. Two characteristic decay time constants are found; fast $({\ensuremath{\tau}}_{1})$ around 0.5 ps slow $({\ensuremath{\tau}}_{2})$ 10 ps....
The self-consistent symmetrised relativistic APW method is employed to calculate the band structures of Sr and Yb at normal high pressure. crystal potential constructed on basis local density approximation. For 4f electrons Yb, however, this does not work well. Therefore, correlation determined for them separately so as reproduce position expected from XPS. results calculations seem be good in Sr. behaviour observed electrical resistivity under pressure well explained by characteristic...
The optical absorption spectra epsilon 2(0, omega ) of Ni2MnSn and Pd2MnSn are evaluated on the basis realistic band structure obtained by tight-binding orthogonalised plane wave (TB OPW) method. transitions between OPW in hybridised states contribute dominantly to main spectra, as was case Cu2MnAl. common properties ferromagnetic Heusler alloys X2MnY (X-Ni, Cu, Pd: Y=Al, Sn) examined using present results those previously for Three peaks below 4 eV a peak above 7 beyond which decreases...